Vulnerability Discussion
Changes to any software components can have significant effects on the overall security of the operating system. This requirement ensures the software has not been tampered with and that it has been provided by a trusted vendor.
Accordingly, patches, service packs, device drivers, or operating system components must be signed with a certificate recognized and approved by the organization.
Verifying the authenticity of the software prior to installation validates the integrity of the patch or upgrade received from a vendor. This ensures the software has not been tampered with and that it has been provided by a trusted vendor. Self-signed certificates are disallowed by this requirement. The operating system should not have to verify the software again. This requirement does not mandate DOD certificates for this purpose; however, the certificate used to verify the software must be from an approved certificate authority (CA).
Check
Verify that all software repositories defined in "/etc/yum.repos.d/" have been configured with "gpgcheck" enabled:
$ grep gpgcheck /etc/yum.repos.d/*.repo
/etc/yum.repos.d/tuxcare-fips.repo:gpgcheck=1
If "gpgcheck" is not set to "1" for all returned lines, this is a finding.
Fix
Configure all software repositories defined in "/etc/yum.repos.d/" to have "gpgcheck" enabled:
$ sed -i 's/gpgcheck\s*=.*/gpgcheck=1/g' /etc/yum.repos.d/*